Police in Glasgow have said they are pursuing an open line of investigation into the sending of parcel bombs to Celtic FC manager Neil Lennon.
Parcel bombs were also sent to a lawyer and a Scottish politician who are prominent Celtic supporters.
Mr Lennon, a Catholic from Lurgan in Co Armagh, stopped playing international football for Northern Ireland in 2002 after a death threat, said to be from loyalist paramilitaries.
At a news conference, Detective Superintendent John Mitchell of Strathclyde Police described the devices as viable and capable of causing considerable harm.
The devices were also sent to Paul McBride QC and Labour politician Trish Godman.
No group has admitted sending the parcels.
A package addressed to Mr Lennon was intercepted at the Royal Mail sorting office in Kirkintilloch, East Dunbartonshire, on 26 March.
On 28 March, a parcel for Trish Godman was intercepted at her constituency office and on 15 April a package was intercepted en route to Paul McBride, who has represented Mr Lennon during his dispute with the Scottish Football Association.
Police have offered safety advice to the intended recipients of the packages, as well as to Royal Mail staff and workers in the mail room at Celtic.
It is the latest in a series of incidents targeting people linked with the football club.
Earlier this year, packages containing bullets were sent to Mr Lennon and to Celtic players Paddy McCourt and Niall McGinn, all three of whom are from Northern Ireland.
